Surface polishing device



Sqfi. 13, 1932. J HANSbN 1,876,923

SURFACE POLISHING DEVICE Filed July 10. 1930 I N VEN TOR.

Zf z'tness. we m 'flu BY A TTORNEY.

Patented Sept. 13, 1932 UNITED STATES PATENT OFFICE.

J'OHN HANSON, F DETROIT, MICHIGAN, ASSIGNOR TO FORD MOTOR COMPANY, OF DEARBORN, MICHIGAN, A CORPORATION OF DELAWARE SURFACE POLISHING DEVICE Application filed July 10,

The object of my invention is to provide a surface polishing device of simple, durable and inexpensive construction.

A further object of my invention is to provide a polishing device especially adapted for polishing painted or lacquered surfaces, such as automobile bodies and the like.

The former method offinishin g automobile bodies ordinarily consisted of spraying lacquer or paint on the body and then rubbing the painted surface by hand until a high gloss was obtained. Buffing wheels have not been successfully used for this work for the reason that such wheels invariably burned through the paint thereby destroying the finish. This burning action is probably due to the relative- 1y high surface pressure of the ordinary wheel.

Bufling wheels have heretofore been constructed of layers of cloth or felt sewed into a disk. The disk is rotated and the work to be buffed pressed against the periphery .of the disk. It will be seen that when such a disk is rotated with sufficient speed to accomplish any appreciable buffing, the centrifugal force of the cloth layers forms a hard periphery for the disk. The disk only bears against the work along practically a line contact so that the unit pressure on the work is very high.

My improved polishing deviceconsists of a sheet of heavy felt cemented to a disk of thick sponge rubber. This sponge rubber disk is covered by a polishing cloth and then mounted on the spindle of a flexible shaft. The circular face or polishing cloth side of the de vice is then lightly pressed against the surface to be polished. The Weight of my improved sponge rubber disk is-much less than that of a cloth or felt disk so that'the centrifugal force and consequentlyits rigidity is much less than the ordinary polishing wheel. Further, the face of my polishi'n'g disk may be pressed against the painted surface and the unit pressure will only amount to a small fraction of the unit pressure of ordinary buffing Wheels.

In my improved device extraordinary flexibility is obtained by providing the thick sponge rubber disk in place of springs, layers 1930. Serial No. 467,048.

through the polishing head of the device shown in Figure 1.

Referring to the accompanying drawing, I have used the reference numeral 10 to indicate generally an electric motor of the portable type. A flexible drive shaft 11 extends from the motor 10, which shaft is housed in a flexible housing 12 so as to be totally enclosed. The free end of the housing 12 is fastened in a handle 13 and the flexible shaft 11 extends through this handle where it is connected to a driving member 14 rotatably mounted in this handle. 14 is threaded so that my improved polishing wheel may be conveniently secured thereto.

My improved polishing Wheel proper consists of a thick felt disk 15 which is fastened to a metal plate 16 by means of several screws 17. A flanged fitting 18 is secured 'to the center of the plate 16, which flange is threaded so that it may co-act with the threads on -the outer end of the driving member 14; I have provided a disk of sponge rubber 19, several times the thickness of the felt disk 15,

which is cemented to the outer face of the The outer end of the member felt disk and which is of substantially the p -same diameter as the disk. A polishing cloth 20 is drawn around both the sponge rubber and the felt disks where it is securely fastened 19, being extremely flexible and light in weight readily deflects to the contour of the various curved portions of the work being polished without exerting an appreciable 5 pressure upon the work. The painted surface is thereby revented from being damaged by burning w ich results with all other polishin wheels known to the applicant.

he novel feature of this device and the one to which I contribute the success thereof is the provision of the thick disk of sponge rubber between the polishing cloth and the rigid portion of the polishing head. This sponge rubber disk is believed to form a new 5 structure in this art and unquestionably functions to give superior results.

Some changes may be made in the arrange ment, construction, and combinationv of the various parts of my improved device without 2o departing from the spirit of my invention, and it is my intention to cover by my claim, such changes as may reasonably be included within the scope thereof.

I claim as my invention:

In a device for polishing painted or lacquered surfaces, a sleeve like handle,- a rigid driving shaft rotatably mounted in said handle having one end screw threaded and projecting out through one end of said sleeve 3 with the other end of the shaft within said sleeve, a flexible shaft in driving connection with said enclosed end, a flexible casing for said flexible shaft detachably secured in said handle whereby a direct drive through said 5 handle is obtained, a flanged fitting threaded on said screw threads having a metal disc permanently secured thereto, said threads being of such direction that normal rotation of the flexible shaft tends to tighten the fitting and said threads," a felt ring of materially larger diameter than said metal disc rigidly secured theretosaid ring having an axial opening therein substantially equal to the diameter of said flange fitting, a flat disc of sponge rubber several times the thickness of the felt disc and of substantially the same diameter cemented to the outer face of said felt disc,and a polishing cloth drawn around the sponge rubber and felt disc and metal plate, said cloth being securely fastened thereto by means of a draw string whereby the edges of said rubber disc will be relieved.

JOHN M. HANSON. 

